1. Field of the Invention
The present invention relates to safety lock mechanisms and particularly pertains to a new and improved cargo trailer safety lock mechanism that effect the latching and/or blocking of cargo trailer doors associated with a trailer positioned on conventional flatbed railroad cars.
2. Description of the Prior Art
The use of latch mechanisms in association with trailers is known in the prior art. Trailers of this category are positionable upon an associated flatbed or flatcar of a railroad or deck of a ship where such trailers are mounted during transport. In an effort to thwart theft and unwarranted into the interior of such trailers various latch mechanisms have been employed. For example, U.S. Pat. No. 3,580,185 to Bridge utilizes a series of overlying crossbeams extending over a first lower container and accordingly forms a support for an upper container wherein these beams utilize centering domes for controlled vertical movement with respect to a deck of an associated railroad flatcar. A second embodiment of the invention positions the domes at opposite sides of the aforenoted deck and then placed along the deck to accommodate containers of varying lengths and are further mounted on the noted deck for vertical shifting. A second embodiment enables the domes or latching mechanisms to be mounted directly on a lower container with a second container supported directly on the lower container. While a solution for securing stacked containers on a railroad flatcar, the Bridge patent fails to provide an effective means for efficiently and easily preventing intrusion into a railroad transported piggyback-type trailer.
U.S. Pat. No. 4,163,425 to Bedard sets forth an anchoring system for securing a trailer to a flatcar utilizing a beam securing the flatcar with an associated slideway formed in the beam with an anchoring member slidable in the slideway employing a prong engageable into an aperture into the corner posts of the associated trailer. The Bedard patent, as may be appreciated, sets forth an effective means of anchoring a trailer onto a flatcar, but fails to set forth an effective means of latching and maintaining trailer doors against unwarranted intrusion.
U.S. Pat. No. 4,347,023 to Rizos sets forth a securement system including a locking bolt biased towards a position for releasing a pin that maintains the locking bolt in a securement mode. When the pin is repositioned in a blocking element reoriented, the locking bolt is released and due to the biasing action, moved out of position where it secures the pin in a hold orientation. The Rizos patent is of interest relative to a latch mechanism but is of a structure and organization generally remote from that of the instant invention.
U.S. Pat. No. 2,775,855 to Leitner sets forth a securement means for maintaining a trailer on a railroad flatcar and merely includes a cooperating series of "U" shaped brackets secured to the trailer and flatcar with pins therebetween for maintaining the orientation of the trailer to the flatcar.
U.S. Pat. No. 3,088,670 to Harlander sets forth a cargo container securement means employing a series of flexible securement elements for tensioning a transport unit on a transport deck and as in other art of this nature, fails to provide an effective and efficient means of latching trailer doors on a piggyback type trailer in association with a railroad flatcar or other comparable transport deck.
As such, it may be appreciated that there is continuing need for a new and improved cargo trailer safety lock mechanism which addresses both the problem of ease of use and effectiveness, and in this respect, the present invention substantially fulfills this need.